Domino games have their own vocabulary, and most of it is never explained to you — it is just used, at speed, by people who have played for years. Here is what the words mean.
The equipment
Term
What it means
Boneyard
The face-down pile of undealt dominoes you draw from. Also called the pot. “Bones” is an old word for dominoes, which is where it comes from — they were once made of bone.
Pips
The dots. A 9-4 has thirteen pips, and thirteen is what it costs you if you are caught with it.
Double
A domino with the same number at both ends. There are thirteen of them in a double-12 set.
Engine
The double placed in the middle at the start of a round, which every train must start from. The 12-12 in round one, the 11-11 in round two, and so on.
Train marker
The token showing that somebody’s train is open to everyone. On screen it is shown on the train itself rather than as a separate piece.
The trains
Term
What it means
Personal train
The line of dominoes belonging to you, which starts from the engine. Normally only you may add to it.
Open train
Someone’s personal train that anybody may now play on, because they could not play after drawing. Also called a public train.
Closed train
A personal train that is private again — its owner played on it, so the marker comes off.
The Mexican Train
The shared train nobody owns, which anybody may play on at any time. More here.
Branch
Where a train splits in two after a double is covered, if your rules allow it.
Playing
Term
What it means
Satisfying a double
Covering a played double with a matching tile, so normal play can continue. Also “covering”.
Going out
Playing your last domino and ending the round. You score nothing; everybody else counts what they are holding.
Blocked
A round that ends because the boneyard is empty and nobody has a legal move. Everybody counts up as normal.
Passing
Ending your turn without playing, after drawing. Your train opens up.
Washing
Shuffling the dominoes face down before the deal — from the way they are pushed around the table.
Blake’s rule
The get-out for playing a double as your last tile with an empty boneyard: the round ends rather than deadlocking. Explained here.
Scoring
Term
What it means
Round score
The pips left in your hand when the round ends. The winner scores zero.
Running total
Your round scores added up. Lowest wins the game.
Double blank penalty
An agreed fixed score — often 25 or 50 — for being caught with the 0-0, which is worth nothing by pips. More here.
